Wild winds mess with bird brains
Hurricanes and global warming are pushing migratory birds off course, and all kinds of unusual species are finding their way to UK shores.
Britain’s avian immigration figures are set to soar to a record level this year. Birdwatchers say hurricanes and severe weather in North America and Asia have caused major disruptions to bird migrations across the globe and swept an unprecedented number of species towards the British Isles.
Birds winging their way to their breeding grounds on the other side of the Atlantic or in the Pacific have been left stranded in Britain and Ireland, adding their numbers to native species.
Twitchers, as the most fanatical birdwatching enthusiasts are termed, have already observed a total of 442 species in the British Isles this year. The highest number ever spotted in one year is 445, in 2008. “We only need three more and we will have equalled our record – I’m very confident we are going to see the record broken before the end of the year,” said Lee Evans, who runs the British Birding Association.
Last month a Siberian rubythroat - a tiny brown bird with a scarlet chest - was spotted outside Lerwick in Shetland. A native of east Asia, it is extremely rare in Britain, but has now spent the past two weeks at the very northern edge of the nation, caught by the cameras of twitchers who have flocked to the island.
Similarly, a bufflehead - a small duck with a distinctive bulbous head - was spotted in a farm pond on the Lizard in Cornwall. “It was absolutely knackered when it arrived,” said Evans. “It had been migrating south from Canada to southern United States when it was swept out into the Atlantic by a storm. It had probably travelled more than 3,000 miles, which explains why it was knackered.” The bufflehead has since flown on, probably to Portugal, he added.
Evans said that global warming over the past decade was playing a key role in transforming bird movements across the globe. Climate change was transforming weather patterns, causing a dramatic rise in hurricanes and storms, particularly over the Atlantic.
“In the 1990s the average total for numbers of bird species spotted every year was 412,” he added. “Now that figure is around 440.
That is a very significant change and global warming lies at the root of it.” In addition, melting Arctic sea ice may be involved. Ornithologists have suggested that the disappearance of ice cover is opening up migration routes over the north pole, making it easier for birds from the Pacific to reach Britain - such as the slaty-backed gull, a native of the north Pacific, which appeared in the Thames estuary this year. A tufted puffin from the north Pacific, a mediumsized black seabird with distinctive white facial markings, was recently seen in the UK, though only a handful of spotters were involved and they only got a brief glimpse. The jump in bird species numbers in the British Isles is good news for twitchers, who obsessively follow news of sightings in order to add rare species to their lists - though the increase does pose financial problems for the birdwatching community.
“It is an incredibly expensive hobby to keep up,” said Evans. “Most of the rare visitors arrive in the Scillies,the Outer Hebrides, Orkney or Shetland - all at the fringes of the British Isles. Flights can cost GBP600 to get there.
“The alternative is to drive, then take the ferry. Every year I run up about 70,000 miles on my car doing this. That means spending thousands of pounds just on petrol. Essentially, I go through a car a year to spot these birds. And now we are getting more and more of them.”
The Bufflehead duck has been pushed off its migratory course
between Canada and the US and wound up in the UK.